I have a Telerik UI for WinForms application that builds and runs fine when targeting the x86 platform. As soon as I change the target platform to x64 the same application will build without issue, but the application will throw an exception when running in Debug mode, stopping on the ThemeResolutionService with a type initialization error. My application is using the 2020.2.616.40 version of the controls and .NET Framework 4.6.1. All application themes are set to "ControlDefault", so this should not be an issue.